1. Field of the Invention
The present invention relates to a rapid manufacturing process of ferrous and non-ferrous parts using a plasma electron beam, and more particularly, to a rapid manufacturing process of ferrous and non-ferrous parts using a plasma electron beam in which ferrous and non-ferrous three-dimensional (3D) parts may be rapidly manufactured by supplying a ferrous and non-ferrous powder onto a laminated plate, emitting a plasma electron beam, and repeating processes of preheating, melting and laminating, and remelting the ferrous and non-ferrous powder.
2. Discussion of Related Art
Recently, in manufacturing industries for products such as cars, aircrafts, molds, power generation parts, engine parts, and strategic parts and in medical industry, interest in a rapid manufacturing technique of special metal parts is increasing. Usually, a rapid manufacturing technique is a method of manufacturing parts by partially emitting an electron beam to a laminated material powder and melting and laminating the laminated material powder.
ARCAM AB Ltd. in Sweden has been developed a rapid manufacturing process (an electron beam melting (EBM) process) and a manufacturing system using an electron beam and a powder supply devices for a powder bed, is beginning to dominate the market, and is also seeking to expand its market. In the rapid manufacturing process (the EBM process) of ARCAM AB Ltd., a 3,500 Watt class hot-cathode electron beam is used as an electron beam and a high vacuum pressure beam preheating, melting, and laminating method is used. In addition, scattering of a material powder is controlled through base high-temperature heating and narrow-width electron beam heating. However, there is no remelting process of the material powder. A manufacturing rate ranges from about 55 cm3 to 88 cm3 per hour. Some materials such as Ti and CoCr are used as the powder.
ARCAM AB Ltd. has a patent, United States Unexamined Patent Application Publication No. 2014-0348691, having the title “Method and Apparatus for Additive Manufacturing.” The above patent relates to a rapid manufacturing process in which parts are manufactured through near-net shape forming by preheating, melting and laminating using a hot-cathode electron beam.
In the Technical University (TU) of Munchen, basic research on a rapid manufacturing process for manufacturing metal parts for near-net shape forming using an electron beam sintering process is progressing. Beam power is about 10 kW, and materials such as H13 steel, H11 steel, CuSn20, FeNi, and NdFeB are used. The rapid manufacturing process of TU Munchen, which is a process of manufacturing parts through near-net shape forming by sintering a metal and non-metal powder using a hot-cathode electron beam, is a high vacuum pressure sintering and laminating method. There is no remelting process of the metal and non-metal powder and basic research on a process impact and mechanism analysis technique is progressing.
Sciaky Inc. in the United States has an electron beam welding (EBW)-based rapid manufacturing process technique. The rapid manufacturing process using EBW is a process in which a final shape is generated by mechanically processing a metal or non-metal after the metal or non-metal is welded using an electron beam. In this regard, Sciaky Inc. has a patent, U.S. Pat. No. 4,376,886, having the title “Method for Electron Beam Welding.” The above patent, which relates to an EBW process, relates to a seam welding method using an electron beam.
InssTek Inc. in South Korea is developing a laser cladding-based metal three-dimensional (3D) printer. The 3D printer laminates materials in a laser cladding method, uses a fiber laser, and has a surface roughness of around 200 μm. Further, when the 3D printer is applied to a material having a high melting point, a production rate of parts is slow and there is a limitation in application.
Filed techniques in Korea related to rapid manufacturing process techniques will be described next.
A superalloy part and an apparatus and method for forming a coating thereon are disclosed in Korean Patent No. 10-0626777 which relates to a method of forming an insulation coating layer by physically depositing a ceramic on superalloy parts by using an electron beam.
Further, a real-time monitoring and controlling method for a height of a cladding layer using image photographing and image processing in laser classing and direct metal molding techniques are disclosed in Korean Patent Application Publication No. 10-2003-0039929 which relates to a measuring and controlling a height of a cladding layer by using image photographing and image processing in a laser surface modification technique such as laser surface alloying and laser cladding, and in a laser cladding-aided direct metal manufacturing technique. In the above invention disclosed in Korean Patent Application Publication No. 10-2003-0039929, a height of a cladding layer is adjusted by real-time monitoring a position and height of a molten pool and simultaneously controlling process variables.
As described above, in the conventional methods, a ferrous and non-ferrous powder is sintered or melted by using a hot-cathode electron beam. There is a disadvantage in that the hot-cathode electron beam requires frequent replacement of a Ti filament thereof, a laminating time of a metal layer is increased due to a limitation of beam power and a beam width, much equipment cost is caused due to a requirement of a high vacuum pressure environment, production costs are increased, and workability is degraded due to a lot of working time.
Further, in the conventional methods, since materials used are limited to three species in the Ti family and one species in the CoCr family and air holes are generated on surfaces of parts while the parts are manufactured, there is a disadvantage in that a quality of the parts, such as surface roughness, density, corrosion property, and hardness, is degraded.